Reroute Traffic

[brent.smith]

Below is a diagram of my network. I have to locations, Atlanta and Dallas.

Both location have there own Internet Access via a T1 circuit.

Both location are connected via a dedicated T1 circuit.

All Inside nodes in Atlanta use RouterB as there default gateway.

All Inside nodes in Dallas use RouterC as there default gateway.

My question is this:

If the Atlanta Internet T1 circuit goes down, how do I configure Atlanta RouterB to identify the down circuit and reroute inside network source traffic destined for the Internet out the Dallas T1 Internet circuit via the dedicated T1?

Atlanta----RouterB----PIX----RouterA---T1---Internet

......................|

......................|T1

......................|

Dallas-----RouterC----PIX----RouterD---T1---Internet

[siddiquiabdul]

- Assuming that you are doing static routes on router B & router C to the pix firewalls,..You will have to put a T1 between router A & router D to get the desired failover..

You are getting into the issues of static routes & its convergence with dynamic routing failover...

[brent.smith]

Correct... So without adding another circuit, what is the the best way to setup dynamic routing so my network will failover?

[wbaker17]

Brent

Policy routing would provide a fairly easy solution in your case. Take a look at this CCO link. This shows an example of a particular subnet being policy routed to pass through a PIX. Ignore the PIX and focus on how the traffic is being directed through a specific interface by a route-map on the router named Cisco_WAN_Router. In your case you want Internet bound traffic to exit out one interface when that circuit is available and exit out of another interface when the primary Internet circuit for that location is down.

http://www.cisco.com/warp/public/105/36.html

Hope this helps

Bill